The present disclosure relates to calibrating an equalizer in a front-end receiver.
Equalizers are commonly used in receiving devices to compensate for signal distortion incurred when a signal is transmitted across a communication channel. One common source of distortion is inter-symbol interference, where the value of a currently received symbol is distorted based on the value of previously or subsequently transmitted symbols. A decision feedback equalizer is a particular type of equalizer designed to compensate for distortion from inter-symbol interference arising from previously transmitted symbols. The decision feedback equalizer estimates this distortion in a received input signal and adjusts either the signal itself or sampling threshold of the signal, based on the previously received symbols. In this way, the decision feedback equalizer seeks to cancel out the inter-symbol interference effect and recover the transmitted signal. For best performance, a decision feedback equalizer should be properly calibrated. Calibration ensures that the equalization parameters are accurately tuned based on the actual characteristics of the channel and the receiver hardware.